Limelands

The arctic north eventually ends in Echos, leading to the foggy seas of the Limelands. Anyone who has crossed the border into this land has never been seen again. However, the first exploratory vessel to be able to send information back to its land base in 1885 describes nothing but coasts of limestone, or petrified bone. The vessel vanished.

In 1911, a zeppelin airship made the expedition again, where the first low-res photos were taken. The fog of the warmer waters plus the endeavor of taking such photos from a zeppelin made them practically useless for studying the geology, but mapped the first beach of the Limelands in The Known World. There was then a report of lack of oxygen, and then communications with the zeppelin went dead.

In 1950 the expedition to obtain samples from the beach resulted in grisly failure as a full radio communications log documents the expedition team's descent to panic and eventual death.

We have no idea whats in the far North except warmer temperatures, lack of atmosphere, and a few beaches of nothing but limestone.

Yeah. Really not great place for kids in Echos to hear about.